I work in h2s environments. That stuff is extremely nasty and can kill you right quick. Even a small dose if it knocks you down, can leave you with permanent damage.
I had a union friend get ‘caught’ in H2S leak at refinery when he tore off his oxygen mask because no air was coming to his mask (someone stepped on hose) and ran out of danger. The Sulfur went right to his brain and lost memory about the whole day and he couldn’t remember enough facts to report it.